Vinylidene chloride interpolymers are well-known in the prior art for their excellent barrier to the mass transport of atmospheric gases and moisture vapor. Because of their excellent barrier properties, vinylidene chloride interpolymers are well suited for use in food packaging operations and other similar operations, wherein it is desirable to protect a given article from oxygen and loss of moisture.
While conventionally made films of vinylidene chloride perform adequately, these films have not been completely satisfactory in use. For example, consumers are interested in the ease of dispensing and tearing off a sheet of film as it is withdrawn from the container in which the film is packaged. Manufacturers have attempted to comply with this consumer demand by supplying containers, such as cartons, which are ordinarily provided with sharp edges, usually a saw-toothed edge known as a cutter bar. The films can then be withdrawn from the container to a desired length and severed along the cutter bar with ease.
Generally, films of vinylidene chloride interpolymers have inadequate strength in the machine direction, which causes the films to tear in strips during dispensing and handling. This tearing is problematic for consumer films, due to the notch sensitive nature of the film. Thus, it may be difficult to restart proper dispensing of the film.
Accordingly, it is an object cf this invention to provide a film of vinylidene chloride which has good barrier to atmospheric gases and good handling properties, such as high strength characteristics and easy cutter bar tear.
It is another object of this invention to provide a process for the production of films of vinylidene chloride having good barrier to atmospheric gases and good handling properties, such as high strength characteristics and easy cutter bar tear.